If $a + b = -8$ and $x + y + z = 3$, what is $-10z - 10x - a - 10y - b$ ?
Solution: $= -a - b - 10x - 10y - 10z$ $= (-1) \cdot (a + b) + (-10) \cdot (x + y + z)$ $= (-1) \cdot (-8) + (-10) \cdot (3)$ $= 8 - 30$ $= -22$